Some very smart people say that the big banks aren't really focusing as much on the lending business as smaller banks.

Specifically since Glass-Steagall was repealed in 1999, the giant banks have made much of their money in trading assets, securities, derivatives and other speculative bets, the banks' own paper and securities, and in other money-making activities which have nothing to do with traditional depository functions.

Now that the economy has crashed, the big banks are making very few loans to consumers or small businesses because they still have trillions in bad derivatives gambling debts to pay off, and so they are only loaning to the biggest players and those who don't really need credit in the first place. See this and this.